How to Upgrade your Vintage Honda CB175 / CB200 / CB350 / CB360 & CB450 Regulator and Rectifier

We officially have a CB175/CB200 supplement to this video! Be sure to watch this for the differences you need to know when installing your CB175, CL175, SL175, CB200, or CL200 regulator/rectifier combo unit. Link: • How To Upgrade Your Ho...
The charging systems on all the old CL and CB Honda twins are weak at best. The factory voltage regulator (limits total voltage to the battery ) and rectifier (converts AC to DC) were barely up to the task back in the day. Add 40 years of heat, weather, and previous owners' wiring hacks, and no wonder the battery on your bike is always dead. Well, we put our heads together and made an easy to install and affordable Honda replacement regulator / rectifier combo kit. This modern Honda CB350, CB360, CB450, CB500T regulator / rectifier combo is a single unit that replaces both factory parts. This is the single best electrical upgrade you can do to your Honda next to our halogen H4 headlight.
CB175, CB200, CB350, CB360, CB450 Regulator/ Rectifier Combo Unit:
www.common-mot...
CB550 Regulator/ Rectifier Combo Unit:
www.common-mot...

[@Common-motor]

We officially have a CB175/CB200 supplement to this video! Be sure to watch this for the differences you need to know when installing your CB175, CL175, SL175, CB200, or CL200 regulator/rectifier combo unit. Link: kzbin.info/www/bejne/j2HEqYlsd86KfZI

[@lolerlol666]

Would anyone be able to tell me which one I need for a cb250 (k4 from 72 specifically) thanks :)

[@Common-motor]

@@lolerlol666 The CB250s are essentially just small bore versions of the CB350 and CB360 models. You will want use all of our resources for those bikes as the CB200 is very different from yours.

[@Ohvurr_leveraged]

This channel is important to the vintage honda community. Informative and fun to watch. Keep this going my dudes and dudets!

[@roger4375]

I think this was the perfect video showing how to install the rectifier/regulator combo on a Honda. There is one statement I disagree with, that being this mod has nothing to do with the larger bikes. But it does, larger bikes usually have a 3 phase stator, three yellow wires etc…. You still remove the old rectifier and separate regulator and you still plug the black wire from the new unit to the black wire where the old regulator was plugged into. Just more wires of the same color…. Well done!

[@russellwhitney5824]

This was a much needed re-shoot of the original for this part. Nicely done, thanks for posting!

[@Common-motor]

Yes we know. Thanks for the support!

[@MotoMango]

This is my first time working and rebuilding bikes older than 1990s. Your videos have been a huge help. THANK YOU! 🙌

[@Common-motor]

glad they've helped!

[@udaypothakamury6315]

Got the Regulator & Rectifier for my CB450 K4 and installed it. The bolts are a pain - Only one was used to secure the new unit and did not "embiggen" the hole. also would have been nice to have allen head thingies. The wiring on the new R&R is just enough length to connect with the old connections, an inch longer would have been perfect. it is a tight space to get the bolts in because of the fins on the R&R.. thank you Brendan and CMC for the awesome videos and for sourcing the parts to keep these lovely motorcycles on the road.

[@Crestlemania]

200 rectifier is tucked up above the carbs in a recess in the top bar of the frame. In case anyone was curious.

[@ronalddaub9740]

Yes I appreciate it I need to find out why mine isn't charging

[@YourLifeChanged]

I can’t praise you enough on how much help you’ve been honestly the best Chanel on KZbin for anything vintage Honda you’ve helped me so much with my 1972 Honda CB350, your the best! Keep up the great work appreciate everything!

[@Common-motor]

Thank you for the kind words. Definitely love hearing them!

[@nathanreeves1173]

You guys are great. I love how you guys explain everything you need to know about the components you sell. Thanks for all the help -Nate

[@STBRetired1]

As I look around for upgrading a CB360T ignition to electronics, there are several manufacturers to choose from. You gotta give extra points to the manufacturer who takes the time to make a video explaining about their product and how to install the parts. It gives me confidence that they know what they're doing when they designed the products. Some of the other sellers may only be cheap Chinese knockoffs and I don't want to make them prosperous.

[@stephencrane9150]

Great video, really appreciate you all making these "How To's" for us weekend mechanics

[@jonesismyname]

You earned yourself a new sub from that Simpsons reference. The content and production is pretty good too

[@Common-motor]

There's a lot more where that came from.

[@los_gasolinos]

After watching a lot of your vids, it is about time to say that I love this channel! Keep it up. thanks for sharing your experience and passion! Greetings from Luxembourg, Europe!

[@robertpotter7069]

I purchased two of these about a year ago for two of my Honda motorcycles and just now got around to installing them, one on my 1973 Honda CL350 and the other on my 1972 Honda CL175. The CL350 installation was straightforward and in accordance with the CMC video. The installation on the CL175 was a little different until I finally found the old rectifier just above the carburetors tucked inside of the center frame where the seat meets the gas tank. Luckily, I was able to use the original rectifier mounting bracket for the new CMC regulator/rectifier (RR) and installed it in the same exact location where the old rectifier was located from the factory. The new R/R plug aligned perfectly with the CL175's rectifier plug from the factory harness. I attached the male bullet wire from the new RR to the female bullet wire (by adding about six inches of wire) of the original voltage regulator located around the battery box. As with the CMC video for the CL350 installation, for the CL175, tape up the green and yellow female bullet wires from the harness that originally connected to the factory regulator. To remove and install the unit in the CL175, unbolt the right carburetor from the manifold and carefully lower it to rest on the lower part of the engine without disconnecting the choke linkage and throttle cable. I give Brenden 5+ stars for the video, although I decided to go with an Antigravity battery to try one out in the CL175. I have no electrical items that would drain the battery when the motorcycle isn't running. After a few months, no issues and the new RR maintained the Antigravity charge. The battery in the CL350 is an AGM battery that the previous owner had installed in the motorcycle and, although it is heavy, it can sit without a trickle charger and maintain about 13.5 volts for weeks on end-so Brenden is spot on about the AGM battery and its reliability. A final note-do not buy a coil/spark plug wire replacement from anywhere else besides CMC because the mounting holes may not line-up with the frame holes.

[@Common-motor]

We appreciate the detailed information! We're actually working on an update right now for the 175/200 since they have those few weird differences that you have to deal with during installation. I might add that the original rectifier actually doubled as the harness ground so when doing the replacement you need to re-ground the harness somewhere else on the frame. An easy spot is using the green connection left open by removing the factory regulator. Tap and bullet into and connect the wire to a ring terminal end and bolt it to the closest frame bolt. Lastly, I'm glad it's been working well with your lithium-ion! I'd usually always recommend people going with the Rick's version built specifically for lithium-ion batteries so just keep an eye on the voltage and make sure it's maintaining the charge properly and not overcharging or undercharging what antigravity recommends.

[@nmp3401]

Great video. Appreciate you doing it and helping us keep these old machines on the road!

[@robertdivizio3489]

Some advice: before removing the battery box on a CB 450 be sure to have marked exactly where it fit. The brackets that hold it "float" for lack of a better term. After reinstalling my battery box, I found the bolt holes for the air boxes and side covers would not line up.

[@VladQuake]

You're my favourite Brian Posehn doppelganger. Thanks for the helpful videos.

[@jeffmullinix7916]

I like using shrink wrap for loose wires Makes a real nice and neat installation I also dont like open ends so when I use shrink wrap I leave a little bit sticking out a bit and when I use a lighter to shrink I just pinch the end of the shrink wrap to seal it . That way you dont have to have all that mess latter on with tape . Tape over time will unravel and that messy sticky adhesive collect dirt and grim . With heat shrink that wont happen .

[@danielregan3455]

I love everything common motor does and feels like my local shop in the internets, but after "embiggenin" the holes with a file the old hex bolts from the old regulator were still too big to fit between the new reg/rec. Now I'm digging around for some spare allen bolts to fit. Just a heads up for anyone trying to use the old bolts, and maybe a suggestion to include some new allen bolts with the new reg/rec in the future. Otherwise, if it wasn't for you guys I'd be hopeless and my bike would be unrideable, so, much love and thanks for the Hat!

[@tomdraz3929]

Ran into that same issue. The allen bolts are just a hair smaller, wouldn't work without them though.

[@sonofpear138]

Common motors makes me confident owning an old bike

[@TheGoatMumbler]

In Texas we call that "Wallering out the holes". :)

[@mlbabineaux]

That old rectifier is Selenium. I would definitely change it for a modern silicon rectifier.

[@robandveramckellar8045]

After watching this video, my question for you is would you be able to confirm for me if this applies also to my 1967 Honda CD 175 (6 volt) The rectifier /regulator, that I’m considering buying is with a matching wiring harness with the exception of the black wire that you refer to. On my bike, do you know if the black wire is essential that I loop it back into the existing positive /regulator wiring? Thank you. I believe your video was very helpful as long as it applies to my machine.

[@Aggiesig12]

This video was funny and really helped me out! Thanks guys!

[@noahgoodrichlife]

I have a 1979 cb125 an I was wondering if it has the same system, I appreciate any help, thanks.

[@ronalddaub9740]

Is it a twin?

[@nealevans9436]

Thank you, even though you say the 4 cyl bikes dont use this system, my 1978 cb750 is similar. Video helped me quite a bit. Easy to follow and understand. THANK YOU>

[@Common-motor]

Glad it helped!

[@dieseltu1035]

Do you got any idea how long these will last..I hate breaking down.and only care about reliability

[@oilinmyblood3906]

@@dieseltu1035 Believe Me Brother this is definitely worth installing if you want reliability... and a proper charging battery, and it is a definite must have part for proper reliability, and I'm not sure how long they last for but I think possibly tens of years

[@vaishnav555]

Are the connectors similar or the same? What were the differences? I'm planning to swap the one on my CB750K4 out this week.

[@dougbock8541]

You say the cb550/750 use a completely different system. I have a 74 cb550k0 and was about to purchase one of these units for my bike. Now I'm confused as to what I need. Can you clarify what is needed for the cb550/750, or perhaps post a seperate video? Thanks for all you do! You're a Rockstar!

[@Common-motor]

Hey Doug, its definitely on our list! Until then we do have some tips on our product page for the CB550/CB750 reg/rec we sell. www.common-motor.com/honda-rectifier-regulator-cb550-cb500

[@QuasiMotard]

Woo-hoo, I was the 1000th 👍 on the video! 😉👍 --QM

[@gurkaochtomat]

Great video! CB400 -82 is not specified in the list but can I assume it will work?

[@JamesJohnson-fj2qy]

"Embiggen" has now been added to my vocabulary.🤣🤣🤣🤘🤘🤘

[@chaprick0106]

Thank you very much for doing this video. I'm hoping my 1974 CB450 is very similar.

[@Common-motor]

Hit us up via our website www.common-motor.com if you need support along the way.

[@alanbirch9663]

Just did mine bought unit from sparkmoto and fitted to my cb350 in uk

[@GoBayside]

For the CL450 - the regulator is bolted to the carb throughway - hidden over the tool storage area.

[@TimberPlanners]

@4:57 "Embiggen"? okay, then goes ahead and says "cromulent" - "yes Caleb, cromulent is a perfectly cromulent word" lol

[@HennieBours]

Wat is te resistance I should read when measuring the stator of my 1975 CB200? I read 2 times 2.5 Ohm and 1 time 1.0 Ohm when I interconnect each time 2 pair of coils. Is it to high or normal or can my statorcoils be worn? My battery is not charging. Might also be the rectifier or the regulator. Great great video!!!

[@JoeFen]

i didnt even consider enbigening, i just hammered the tabs down so that there were further apart enough to match.

[@christianbresch7445]

Excellent content guys, I love your channel! Could you put the link to the rigth combo unit for my 1975 Honda CB500Twin?

[@buddymcclure6170]

Will this work for a 74 CB 125s as well? New subscriber as well and thanks for sharing.

[@AhhSamboi]

So I was trying to do this on my 1979 Honda GL100..... The rectifier on my bike just looks like a diode. It's got one wire in and one out😅 how would I go about installing it

[@realscientist]

Nice.. but the drawback of shunt regulator is increasing fuel consumption with more losses of AC current than the it's original linear regulator...

[@johnhenryhanson6998]

Hey! Just picked up a 1972 CB350, and recommendations for a quality replacement seat cover?

[@jord001]

Great Vid, are there any similar mods for the 6v singles? I have an SL125 that was never great for charging and lights. Regards

[@michaelpauley125]

I have a off the wall Question ? Can You Replace A Chain Drive On A Vintage 70's Honda With A Belt Drive ? I Am Sure,Sure I Noticed One On A Vintage Honda 350,At A Bike Swap Meet.

[@donaldyang5569]

Looking for a regulator rectifier to buy for my 1973 cb500. I guess 2 of the big ones I've been seeing are this one from Common Motor Sports and Rick's regulator rectifier. The common motor sports Reg/Rec cost less but is it reliable? Rick's cost more but is it worth it? Can I get some recommendations on this?

[@nichter260]

Hi, Have an old Bridgestone 175,trying to upgrade rectifier. Bike has no stater, it has an AC generator and a 3 phase selenium rectifier. The new solid state unit has 6 wires, with 4 yellow. Any ideas?

[@dbehunin]

Hello, I bought one of these conversions for my 1970 SL350, my wire harness that plugged into the rectifier is a flat in line wire plug. Is there an adapter of some kind to make it work?

[@CycleGeezer-cq9lm]

Will this rectifier/regulator system work for the Honda CB77? Or, do you offer a rec/reg for the CB77 Superhawk?

[@benjaminroot6270]

Hey folks, Is the bolt connection of this unit (to the bottom of the battery box) a functional ground to the frame? Did the elimination of the original rectifier remove a green-wire to chassis connection? How about the removal or the original regulator (did that remove a green to chassis connection)? Thanks!

[@EIKLURAM]

Not sure why you don't mention the CB250 ?

[@elizabethtruman7164]

I recently acquired a TLR 200 reflex it's the earlier version from 79 to 86 I have a 1983 and a 6 volt system I need to change out the rectifier it says rectify regulator on the unit SH542-6 39 6v and I'm making to much voltage when over half revs Is there a replacement in 6v Kindest regards Bell

[@Tyoung83]

Well played with the Hans Sprungfeld reference.

[@michaelpauley125]

I've heard the term round out more,or to say round the hole out bigger.

[@clevelandmotley]

Do you guys have a video for installing your part on a 550?

[@davesharratt]

Do you do a replacement for the 6v system ??

[@elliepersian7792]

Lovin the set!

[@crazylikeafox7341]

I bought an ebay Regulator/rectifier combo that does not have the black "feedback" wire. It only has two yellow, 1 green and one red wires. Can this still be used on a cb175? The plug lines up but I am confused about the old regulator connections. Is the feedback connection essential?

[@Common-motor]

You need to have that wire connected to be able to regulate power. I'd recommend picking up a reg/rec unit from a better know source that has the proper connections. That could cause you some headaches and possibly cook your battery depending on the quality of it.

[@crazylikeafox7341]

@@Common-motor I am considering buying one from your link below. I see there is a coupon code spot at checkout. Are you running any deals at this time?

[@newscooler12316]

Hello I lost my rectifier on my 79 xs400 will any rectifier work? I don't want to upgrade to the 2 in 1 just get a new old fashioned. Thanks.

[@snakeskinner2]

Great video but what is the advantage of this upgrade?

[@bretearwood7027]

Do you have any idea how the older model bikes handled the a.c. voltage range without a regulator? Aside from a field excited system? How does a charging system not use a regulator but still rectify the a.c. to d.c. and send it to a battery?

[@TheNeilcoppley]

My cb200 doesn’t have a plug and it only has a 12 volt regulator?

[@Aperturexplorer]

Does this replacement rectifier work on just lead acid or also lithium ion?

[@daveb1963]

I recently fitted one of these but battery still nto charging so im going to assume stator is at fault,what is your recommendation for replacement...

[@jfdashley9028]

Excellent video.

[@jpvillabona]

i have a cb 125s 1980, would this work?

[@jameshenrytrotter7703]

Where do you guys source these units from? I am super excited about everything you supply, but obviously want to do a little more research when shopping for a new R/R. Thanks for everything! CMC has been a great asset!

[@guerra444]

Mine doesn’t have a black wire does it matter??

[@HennieBours]

I ordered this regulator but it was not plug and play since both the wires of the bike and those of the regulator had a male plug. I had to make the wires longer and change the connection plug of the regulator.

[@vlissblisskiss]

this was an incredibly useful video

[@jthreejk67]

@ 4:04 mins. You show a weird type of cylinder that has green red and yellow red attached to it is that a part of this replacement?

[@Common-motor]

I've watched the video a few times and can't actually find the cylinder you're referring to. At 4:04 we are removing the stock regulator.

[@Whatnow458]

You guys are awesome

[@NightRaven_and_Geopelia]

I live in Japan. I own CB200. I want this regulator.

[@mcnuggieguy]

Get it from sparck moto for half the price

[@htmonaro1969]

I assume the 500/4 is the same as the 550, it's just that the only 500 you mentioned was the 500T. I have a CB 500 K0 project, so the issue is relevant to me. If so, do you have a video on the 4s?

[@austinmonahan7022]

I hope someone could help me. I have a 74' Honda cb200. Changed the regulator and bought a new battery. Starts momentarily but won't stay running and the lights are also not working. Does anyone have any idea what it could be?

[@abelrodgers3927]

Perhaps a dumb question. Does the reg/rec need to be grounded to frame? Meaning the two holes you embiggend do they need to be grounded to frame. Might be redundant. I was thinking about mounting mine to something not grounded to frame.

[@Common-motor]

Nope! They already have a ground wire on it that connects to the harness ground circuit.

[@JourdonGulick]

Is there anything you can do for a '73 CB100?

[@jeffmullinix7916]

I like to ask if you tape off the yellow wire from the stator then are we not going to have a dual phase system . One being extra voltage for the head light and the other dedicated to the charging part . Technically the purpose of dual phase on these twins one single faze is to regulate for the headlight and the other faze is dedicated for charging and keeping up with the rest of the bikes electrical system right ? I am hoping I am saying this right .

[@Common-motor]

Hey Jeff, it's best to combine them its a single, always-on charging system. See our white/yellow wire mod. Honda only had them separate back in the day because the selenium rectifiers of the day couldn't handle the current of the whole charging system without the headlight adding a draw. A modern reg/rec can and gives you the benefit of more charging.

[@HennieBours]

I followed you instructions and installed this regulator on my CB200 but unfortunately the read out with running engine is only a bit above 12V and that is most probably the voltage of the battery. With a running engine I guess I should read a value above 13V. Something is wrong but what? Can you please give me some advice? Thanks.

[@amirv1422]

Don't connect the DC output of the regrec to the charging system and measure it's voltage while the engine is running

[@luhe7794]

Is it working with Lithium (Lifepo4) Batterys? Or is the Output >14,4 volts?

[@Common-motor]

Our reg/rectifier combo unit is made to pair with a Lead Acid/ AGM battery. We haven't tested it with lithium Ion batteries currently. I'd recommend looking for one made to pair with a lithium ion battery.

[@stephencrane9150]

This doesn't work with a Lithium Battery without significantly shortening the life span of the battery. Revival Cycles sells one that works with both, its more expensive but worth it if your running an Li Battery

[@juice2157]

Thanks for the video. I have a 1969 cl125A Scrambler and would like to know if you have regulator/rectifier upgrade for its 6 volt system. Thanks in advance for your response.

[@Common-motor]

I don't currently have a 6v reg/rec. I might check ricks electric, they have a bit more unique electrical gear. If I ever support a 6v bike I'm sure we will either have one made or make a 6v to 12v conversion.

[@halcobb1627]

very helpful videos, thanks for that. Please stop the background music.....makes it hard to hear your message for many of us.

[@waiheke109]

What about combining white/yellow wires in the headlight. Thought this was crucial to getting full output of stator

[@Common-motor]

We released a video of how to do that too with this one, check our channel its the latest video

[@markskennedy]

can I do this with the unit you supply on an SL175?

[@barcusful]

Thanks for sharing

[@jeromeactis]

Hello does it work with the cb250 k4? Tks. A lot

[@SNESChalmers147]

Just recently put together a CB450 with a brand new harness and one of these rectifier regulators and I have a concern that I've not found answers to elsewhere. Engine off, ignition switch off, the rectifier regulator unit still gets hot. Presumably this is an issue? I fully expect it to be hot to the touch when the engine is running, but not any other time.

[@Common-motor]

Hey chris, it definitely shouldn't be getting power with the ignition off. I would do some testing with a multimeter and see what's getting power with the motorcycle turned off. Email our support if you are still struggling!

[@joseescribano4740]

Hi! Can I do the same exactly this in a Honda 1987 CMX450? Thank you

[@mauriceeley621]

Can i buy these in the UK?

[@adlodewijkx6386]

Hi Brenden, thanks for sharing your knowledge! Does it fit on a 1975 Honda CB250G5? Regards from Holland.

[@Common-motor]

Yes! The CB250's are basically the CB360's here in the states.

[@adlodewijkx6386]

Common Motor Collective Thanks!

[@patrickmurray8304]

I presume the 250 is included in this list

[@fvrewell]

Can I use the standard ricks regulator with an antigravity battery?

[@Common-motor]

I would message ricks support but I believe they make a lithium ion specific reg/rec you'll need if you are using a lithium ion antigravity battery.

[@fvrewell]

@@Common-motor thank you so much!

[@gilpul71]

I got a cb350f, is it the wiring the same?

[@Common-motor]

No, the CB350F is actually using a very different type of charging system like the CB500F, CB550f, CB400F and CB750s

[@calebk3255]

I got very confused when u called out Caleb for imbiggened not being a word 😂 i was like i didnt say anything

[@restorwerke]

Hi, does it also fit the Honda cb250k? The connections are identical! And can a lithium battery be used? Thanks for the helpful videos.

[@Common-motor]

Yes this regulator/rectifier works for most of the 12v Honda twins of that era. As for the lithium battery we don't recommend them currently, I would check out our battery choices video to learn a bit more: kzbin.info/www/bejne/iWiki6iImtiihc0

[@jaylin1932]

What's the voltage at battery terminals @ idle RPM? At 5,000 RPM?

[@Austintatious]

Does this Regulator/Rectifier also work with the CB350F by any chance?

[@Common-motor]

no, different style of charging system unfortunately.

[@joemassanova7184]

Hi, I have a 350 and I’m going to swap out the rectifier with your new one. Will the on off switch on the handlebar still work after I upgrade to your new one?

[@Common-motor]

Yes definitely. This is an upgrade to the charging system only. If you do the white/yellow wire mod that also won't effect your switch, the headlight being on or off just will no longer dictate how your stator charges.

[@joemassanova7184]

Common Motor Collective thank you.

[@bigal7561]

Crap. I ordered the two replacement parts rather than the combined unit. Oh well. It'll work as well

[@guitariste47]

Great vid

[@adriankling4115]

I have a 1969 Honda scrambler 350 and when it is idling it runs on one cylinder but has soon As I rev it the other cylinder kicks in. I cleaned both carbs and didn’t do anything. I even took the carb on the cylinder that wasn’t firing and switched it to the cylinder that was firing and it ran the same. So idk any advice?

[@vegardpedersen8651]

Sounds like an electrical issue, have you checked that you’re getting a spark on the cylinder not firing? Common motor collectivevhas a great video on ignition system troubleshooting, i would suggest checking that out.

[@adriankling4115]

Vegard Pedersen yes I’m getting spark on both cylinders

[@MrBigal451]

. the lead from the points going to my right cylinder was shorting out on the metal cover. my right cylinder wasn't firing. Also have you replaced the ignition coils, condenser and spark plug wires and plugs. I had the originals. After I replaced them the bike ran smoother. They were going out causing an interminate firing problems. good luck bry

[@cb400fhonda6]

Superb

[@RaySarasin]

I have a 1981 CB 650 (4) its blue